Telephone connecting block having improved cover locking means



United States Patent [72] Inventor James E. Golden 3,013,105 12/1961 Craig 220/3.8UX Evanstomlllinois 3,112,148 11/1963 Wochner 174/138.4X [2]] Appl. No. 799,357 3,469,681 9/1969 Norman 220/55(C)X [22] Filed d Igeb. 12 FOREIGN PATENTS [45] 36 559 5 1965 o 1 4 66 [73] Assigree Electric 3231034 12/1929 6221151151511 I: 220 2 42 f l 670,644 1/1939 Germany 220/55(B)UX a corporation of Illinois Primary Examiner-Joseph R. Leclair Assistant Examiner-James R. Garrett TELEPHONE CONNECTING BLOCK HAVING Attorney-label, Baker, York, Jones and Dithmar IMPROVED COVER LOCKING MEANS 8 Claims, 10 Drawing Figs.

A telephone connecting block comprises a base 174/51 174/661 220/431220/55, 220/60 and a loosely fitting cover. The cover is made of high impact [51] Int. Cl 1102;: 3/08 polystyrene so that i is Slightly resfliem At one Set f opposite [50] Fleld ofsealch ..ZZO/3.8.60. comers the cover is provided with locking [edges which 55C-55K43; 174/52'66138-4 gage the lower surface of the base. Pressure applied at the 56 R f CT d other set of corners will deform the cover to disengage the l 1 e erences 8 locking ledges from the base and permit separation. The cover UNITED STATES PATENTS has a split pin extending downwardly through an aperture in 461,195 10/1891 Dillon... 220/3.8X the base. A detent formed on one of the legs of said split pin 1,326,885 12/1919 Wales 220/43 provides a snap action which holds the cover onto the base in 2,510,745 6/1950 Kilgore 220/3.8X addition to the locking ledges.

, 1 I l 25 I I I v I Q J6 /7/@ i 26 56 j C 42* f r Z0 5 l I] 3 f 11 Z 11111 6Q I ./7 l. I" 24 I 5 I I l K Sheet 2 of 2 TELEPHONE CONNECTING BLOCK HAVING IMPROVED COVER LOCKING MEANS This invention relates to an improved connecting block for use in making the connection between the instrument wire of a telephone and the line wire which comes into the house.

The connecting blocks in present use comprise a body and a cover, the cover being held by a holding screw which passes through the cover and is threaded into the base. The base has terminal screws which connect each conductor of the incoming line wire to a corresponding conductor of the instrument wire.

Whenever a telephone instrument is replaced. the cover is removed by removing the holding screw.

It is an object of my invention to provide a connecting block in which the covercan be attached or removed without the use of a screw driver or other tools. Also, the elimination of the holding screw improves the appearance.

A further object is to provide a means of attaching the cover to the base in a secure manner in which the cover cannot be accidentally jarred loose by the impact ofa kick or a vacuum cleaner.

Another object is to provide a connecting block which is tamperproof in that it cannot be readily removed by unauthorized persons, although the telephone company serviceman can easily remove the cover by applying slight pressure in the right place.

According to one aspect of my invention, I provide a concealed locking means, the manner of operation of which is not apparent from a visual inspection of the device, after it has been mounted on the baseboard. In this connection, I provide a cover which is somewhat larger than the base so that it can be deformed so as to release the locking means, and additionally I provide positioning means for centering the loosely fitting cover with respect to the base so that the locking means remain normally engaged. Furthermore, the positioning means is located at the center of the base and cover assembly so that it does not interfere with the deformation necessary for operation.

According to another aspect of my invention, I provide two holding means, one being a snap action means operated by movement of the cover toward or away from the base, and the other being a positive interlock of the cover and the base which prevents relative movement of the two in the direction necessary for release ofthe snap action means.

A further feature of my invention is to provision of an arthe instrument wire;

FIG. 5 is a bottom view of FIG. 1 showing a changed position in dotted lines;

FIG. 6 is a plan view ofthe base;

FIG. 7 is an enlarged section ofthe snap pin; and

FIGS. 8, 9 and 10 are views of various strain relief devices which can be accommodated by the connecting block.

The connecter block 11 comprises a base 12 shown in FIGS. 2. 5 and 6, and an overlying cover 13. The cover has one opening 14 which receives the line wire, and a second oppositely disposed opening 15 which receives the instrument wire. Hollow mounting lugs 16 are provided on the base to receive mounting screws, not shown, so that the base may be screwed to the baseboard ofa room.

The base 12 provides four screw terminals 17 which take into nut inserts 18 which are molded into the base, or otherwise secured thereto.

The cover 13 is secured to the base by a split pin 19 which is molded integrally with the cover 13. One of the legs of the split pin has a detent 20 which interlocks with the undersurface of the base. The pin and cover are molded from a slightly resilient thermoplastic material such as high impact polystyrene so that the two halves of the split pin are urged outwardly into the locked position shown. It will be noted that the upper surface of the detent 20 is a cam surface 22 so that the detent leg of the split pin will be easily displaced by an upward pull, and the slot 21 is of sufficient width to accommodate such displacement.

As shown in FIG. 5, two opposite corners of the cover 13 are provided with locking ledges 24 which underlie the lower surface ofthe base 12. In order to remove the split pin I9 from the hole 23, the other two opposite corners of the cover 13 are pressed toward each other as indicated by the arrows 25. This causes the first two corners to be bowed outwardly to an extent wherein the locking ledges are clear of the base 12. Then an upward tug will cam the detent inwardly so that the split pin 19 can be removed from the hole 23.

It will be noted that the cover is enough larger than the base so that there is a clearance 42 (FIG. 5) between the two. This clearance permits the deformation of the cover necessary to the release of the locking ledges. The pin 19 serves to center the cover with respect to the base and to prevent relative sideways movement which might cause disengagement of one of the ledges without application of the deforming pressure.

Spacer ribs 26 formed on the side walls of the cover 13 maintain the desired spacing between the upper surface of the base 12 and the top of the cover. Thus the spacer ribs 26 and the locking ledges 24 cooperate to maintain the cover in a definite position with respect to the base.

' The manner of bringing the wires into the connecting block is the same as in the prior art devices, and need not be described except to point out that the line wire is disposed beneath the base, whereas the instrument wire is brought through the opening 15 and is disposed above the base, there being grooved portions 28 and 29 to accommodate same.

The present connecting block is designed to receive three different types of strain relief clips, the wing type 31 of FIG. 8, the tab type 33 shown in FIG. 9, and the ring type 38 shown in FIG. 10.

On either side of the groove 28 are lugs 30 which interlock with the wings 32 of the strain reliefclip 31, shown in FIG. 8.

In the tab type 33, the tab 34 is bent down and inserted in a U-shap ed slot 35 in the base, with the tongue 36 ofthe slot extending through the hole 37 ofthe tab 34.

In the ring type strain relief clip 38 of FIG. 10, the split pin 19 extends through the ring 39 and locks the instrument wire 40 in position. The base is formed with a 270 collar 41 which locates the ring 39 while the cover is being applied. In this ar rangement, the instrument wire 40 is positively locked into the connecting block 11 as contrasted with the FIG. 8 arrangement in which a strong pull might bend the wings back. Furthermore, there is less possibility of improperly positioning the strain relief device.

Iclaim:

l'. A connecting block for a telephone comprising a generally square base, a generally square cover therefore having a top wall and four depending side walls, locking means located at two opposite corners of said cover and interlocking with-said base, said cover being loosely fitting and resilient so that pressure applied at the other two opposite corners of said cover will cause deformation of said cover to disengage said locking means from said base and permit separation thereof, and positioning means preventing relative lateral movement of said base and said cover, said positioning means being located at a point where it does not interfere with said deformation.

2. A connecting block as claimed in claim 1 in which said positioning means comprises a pin extending downwardly from the top wall of said cover, said base having an aperture receiving said pin, said pin and said aperture being located at substantially the center of said cover and base assembly.

3. A connecting block for a telephone comprising a generally square and a generally square cover therefore having a top wall and four depending. side walls and said cover having a pin extending downwardly from said top wall, said base having an aperture formed therein for receiving said pin, said pin having detent means releasably engaging the base in said aperture, locking means located at two opposite corners of said cover and interlocking with said base, said cover being loose fitting and resilient so that pressure applied at the other two opposite corners of said cover will cause outward displacement of said locking means to disengage same from said base and permit upward movement of said cover and pin.

4.'A connecting block as=claimed in claim 3 in which said base includes a partial collar partially surrounding said aper- V ture for locating the ring ofa ring type strain relief, said pin extending through said pin extending through said. ring.

5. A connecting block as claim 3 in which said pin is a split pin having two resilient legs separated by a slot, said detent means being located on one of said legs, and said slot being of sufficient width to accommodate inward displacement of said I detent leg pursuant to movement of said cover away from said base.

6. A connecting block as claimed in claim 3 in which said locking means comprise ledges extending inwardly from the side walls of said cover and engaging the under surface of said base.

7. A connecting block as claimed in claim 6 in which said cover is provided with spacer ribs on said side walls engaging the upper surface of said base and cooperating with said locking ledges to maintain said cover in a definite vertical position with respect to said base.

8. A connecting block for a telephone comprising a generally square base and a generally square cover therefor having a top wall and four depending side walls and a pin extending downwardly from said top wall, said base having an aperture formed therein for receiving said pin, said pin being a split pin having resilient legs separated by a slot, a detent on one of said legs having a cam surface engaging the lower edge of said aperture, the slot being of sufficient width to accommodate inward displacement of said detent leg pursuant to upward movement of said cover and split pin, locking ledges extending inwardly from said side walls at two opposite corners of said cover and engaging the undersurface of said base, said cover being resilient so that pressure applied at the other two opposite corners of said cover will cause outward displacement of said locking ledges to disengage same from said base and permit upward movement of said cover and split pin.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 542 233 Dated 7 November 24. 1970 Inventor(s) lames E g ld It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

001.2, line 61, change "therefore" to --therefor--.

001.3, line 2, after "square" insert --base--;

same line change "therefore" to --therefor--.

SIGNED ms swan Atteat:

Edward M. Fletcher, 1:. mm E- SGHUYLER, J Officer Gemissioner of Paten1 

